Production of ethees



Patented Aug. 26, 1941 2,252.12: rnonuc'rlon or ETHERS Leonard 1'.Moore, Stamford, Conn., American Cyanamid Company, N. Y" a corporationof Maine No Drawing. Application assignor to New York,

March 9, '1929,

Serial No. 260,778 2 Claims. (Cl. 260-615 This invention relates to thepreparation of various ethers by the reaction of an alkylene oxide withan organic compound containing one or more hydroxyl groups.

One object of this invention is to devise an improved catalytic processfor the preparation of ethers from alkylene oxides and alcohols. Anotherobject of this invention is to provide an eillcient catalyst for thereaction of alkylene oxides with alcohols or other hydroxyl compounds.

These and other objects are attained by reacting an alkylene oxide withan organic hydroxyl compound such as an alcohol in the presence ofstannic chloride as a catalyst. Preferably anhydrous stannic chloride isused.

The following examples, in which the proportions are given in parts byweight, are given by way of example and not in limitation.

Example 1 100 parts of. glycerol containing 1% stannic chloride areheated to 125'-140 C. and ethylene oxide is bubbled through the glycerolfor about sixteen hours at which time about 84 parts of ethylene oxidewill have combined. The resulting product is an ether mixture which hasan average molecular weight of about 167.0 as calculated from adetermination of the hydroxyl groups.

Example 2 2000 parts of triethylene glycol and 22 parts of stannicchloride are placedin a suitable reaction chamber provided with anagitator and surrounded by a heat transfer bath. The reactiontemperature is maintained at about 25-35 C. and ethylene oxide is addedslowly. It requires about five hours to add about 1714 parts of ethyleneoxide. After the addition of the ethylene oxide the temperature isgradually raised to about 45 C. and held for suflicient time to completethe reaction, e. g. one-half hour. The average molecular weight of themixture of glycol ethers as calculated by determination of the hydroxylvalue is about 320. While the product is light brown, this color isapparently due to the catalyst.

Example 3 A product made according to Example 2 is fractionallydistilled to give the following fraclent tin hydroxide.

Example 4 Aproduct made according to Example 2 is diluted with fromabout one-fourth to about an equal volume of water. The mixture is thenallowed to stand until the catalyst (e. g. about twelve hours) in theform of floccu- Decolorizing carbon may be added if desired and then themixture is filtered. The completeness of the precipitation may be testedby passing hydrogen sulfide into a small sample of the filtrate. If noprecipitate be formed, the precipitation with water is-complete.

The clear filtrate is warmed on a steam bath and a vacuum applied toremove the w ter present. The product is clear yellow and has an averagemolecular weight of about 268.

Example 5 Example 2 is repeated except that a higher reactiontemperature is used, e. g. about 45 C. (115). In this way about 2200parts of the ethylene oxide react with the glycol. The yellow product istreated with water to precipitate the catalyst, a filter aid added,filtered and dried, substantially as described in Example 4. Air may .bebubbled through the mixture during the removal of water and theresulting product is al most water white. The average molecular weightof the polyethylene glycol mixture is about 278.

Example 6 in the manner described in Example 4. Hydro-- gen sulfide maybe bubbled through the product to assist in the precipitation of thecatalyst if desired. The average molecular weight of the mixture isabout 230-235. The mixture of glycerol ethers may be separated intovarious fractions by distillation if desirable. The low boilingfractions are colorless while the high boiling fractions arebrown, thecolor changing gradually as the distillation temperature rises. Themixture distills over a wide range between about 100 C. and

tions.

Color ggi g a Boiling range :32: Principal glycols present mm. AColorless to light yellow..- 215 l67l90 C 2. 3 Tetrsand onto-ethyleneglycois. B do 277 195-215 0-- 2.3 Pentaand exa-ethylene glycols. 0 Brown363 Residue Hexaheptaand cote-ethylene glycols.

Some of the color may be removed by agitation with decolorizing carbonand filtration.

about 260 C. at about 23 mm. pressure. The fraction boiling betweenabout C. and about has precipitated Example 7 f Triethylene glycol andethylene oxide are reacted in the same general manner as describedsins,

Example 2 and the catalyst is separated as described in Example 4. Thefollowing table shows the proportions of reactants and catalyst as wellas the properties of the resulting products:

Aviarage mo wt. Parts of igg Parts of calculated z g triethylene e gstannic from i glycol combined chloride molecule nation Example 8 242parts (5 mols) allyl alcohol and about 3 parts of stannic chloride arecooled to 5-10 C. in a suitable reaction chamber. About 290 parts (5mols-i-about 10% excess) of liquid ethylene oxide are added slowly withagitation. After the reaction is complete the catalyst is removed andthe product dried as described in Example 4. The resulting product issubstantially water white. It may be distilled if desired, to give thefollowing fractions:

Avlerage nug Distillation ll ar weig 1;

Pressure (calculated temperature from y xyl value) 1 100 Atmos 2 162 d104 3 65 1 mm 141. 5 4 3 1 mm 190 Example 9 290 parts (5 mols) of allylalcohol and about 485 parts (10 mols+about 10% excess) of liquidethylene oxide are reacted in the presence of about 3 parts of stannicchloride in the same way as described in Example 8. The product may bepurified by the procedure of Example 4 to give a water white or paleyellow product.

The reactions illustrated'above may be carried out using other organichydroxyl compounds including monohydric alcohols, dihydric alcohols, thehigher polyhydric alcohols such as polyglycer- 01, and phenols. Amongthese compounds are: methanol, ethanol, propanol, butanol, cyclohexanol,octanol, dodecanol, benzyl alcohol, ethylene glycol, diethylene glycol,propylene glycol, bu-

tylene glycols, octadecanediol, glycerol, glycerol the higher glycolssuch as tetraethylene glycol, phenol, cresol, naphthol. etc.

Similarly any 01' the alkylene oxides may be substituted for ethyleneoxide such as propylene oxide, butylene oxide, cyclohexene oxide, etc.

It has been found that only small proportions of stannic chloride arenecessary to catalyze the reactions efliciently. Accordingly from aboutV2% to 5% (based on the weight of alcohol or the weight of alkyleneoxide to be reacted) oi catalyst is generally sufllcient. Usually about1% of catalyst is preferred.

Any suitable reaction temperature may be employed. It has been foundthat the reaction between the alkylene oxide and the hydroxy compoundwill take place at relatively low temperatures, e. g. just somewhatbelow room temperatures but obviously the reaction will proceed morerapidly at temperatures higher than room temperature. Accordingly it isdesirable to use the highest reaction temperature which is possiblewithout the loss of large Proportions of either the alcohol or theallwlene oxide by volatllization.

While it is generally more convenient to con- (met the reaction atatmospheric pressure, it is also possible to operate the process atpressures above atmospheric in order to reduce the losses byvolatilization and/or to increase the proportion of combined alkyleneoxide.

Many useful products may be prepared by means oi the reactions describedabove and the resulting products find wide application as solvents, asreactants in the preparation of alkyd resins. etc. Mixtures ofpolyethylene glycols such as those prepared according to Examples 2, 5,and 7 are particularlysuitable for the preparation of flexible resins.Similarly the glycerol ethers such as those prepared according toExamples 1 and 6 find use in preparation of flexible resins. Allylethers such as those prepared according to Examples 8 and 9 find use inthe modiflcation of various resinous materials.

Obviously many modifications in the processes described above may bemade without departing from the spirit and scope of the invention asdefined in the appended claims.

I claim:

1. A process of producing simple ethers of triethylene glycol whichcomprises adding ethylene oxide slowly to triethylene glycol in thepresence of stannic chloride at about 25-35" C. and at atmosphericpressure and subsequently raising the temperature to about 45 C. tocomplete the reaction and maintaining the temperature at 45 C. for aboutone-half hour.

2. A process of producing substantially pure simple ethers oftriethylene glycol which comprises adding ethylene oxide slowly totriethylene glycol in the presence or stannic chloride catalyst attemperatures of about 2535 C., subsequently raising the temperature toabout 45 0., maintaining the temperature at 45 C. for. about onehalfhour, mixing the product thus formed with monoand diethers, glycerolmonoand diesters,

about one-fourth to an equal volume of water, thereby precipitating thecatalyst as fiocculent tin hydroxide, separating the tin hydroxide fromthe mixture and removing the water present in the mixture.

LEONARD P. MOORE.

,Patent No. 2,253,723.

cnnnnc m or comcnon; e

Aug 'u at z," 119 4 i woman P. noo'ms'. It is hereby certifiedthat-error eppear'e inthe prihted specification of the above numbezeedpatent requiring correction as follows: Pagel, first column, Example 5',iii the table, under the heading "Pressure mm", for "2.5" bothoccurrences, read 2-5 and the t the said Letters P atent should be readwith this correction therein that the same may conform to the record ofthe case in the Patent Office.

Signed and .sealed this 50th dey of September, A', D. 1914.1.

Henry Van Arsdale, (Seal) Acting Commie sioner of Patents,

